In this work it's analized the system on the deck of a tanker for cargo handling (loading and unloading) and other related systems important for cargo control and ship safety. Since most of the cargo transported by tankers is highly flammable, detection of possible leakage from the tank is also required. This is the responsibility of the gas detection system in ballast tanks and dry areas around the cargo tank. The oily water discharge monitoring system is in charge of preventing excessive pollution of the sea with oily water that remains on board after washing cargo tanks. The remaining two systems are not directly related to the cargo itself but are important for the stability of the ship, and these are the systems for measuring the level in the ballast tanks and measuring the draft. My own experience gathered by sailing on tanker ships as engineer helped me with the work, I have also gathered knowledge in this field from conversations with experts who had installed and serviced cargo tank monitoring systems.